DESCRIPTION: (Applicant's Abstract) The proposed study applies the new analytic framework of multilevel (hierarchical) modeling to data from two large, nationally representative samples of adolescents (the National Household Survey on Drug Abuse (NHSDA), 1992 and 1993 (N= 14,232), and the National Educational Longitudinal Study (NELS), 1988-1992 (N=24,599)) in order to explore how neighborhoods and schools (defined generally as communities) condition the relationships among family structure, individual-level school variables, and drug use and delinquency. The specific aims are to assess how community-level variables defined at the census tract or block level affect adolescent drug use and delinquency; to explore how these community-level variables affect the relationship between family structure and adolescent drug use and delinquency; to examine the role that schools play in mitigating or amplifying the negative effects of individual-level school-related variables on adolescent drug use and delinquency; and to investigate complex interactions between community-level (neighborhood and school) variables, family structure, and individual school-related determinants of adolescent drug use and delinquency. The study uses macro-level data (census tract, block level, and school-related) that have been linked with individual-level data in the two data sets to carefully model how community-level characteristics condition the effects of family structure (e.g., single parent vs. two biological parent families) and individual-level school variables (e.g., attachment and commitment to school, academic achievement) on adolescent drug use and delinquency. Recently developed statistical models (generally known as hierarchical or multilevel models) and software for estimating these models (e.g., HLM, MLn) are used to analyze the proposed hierarchical effects. The results will enrich theoretical descriptions of community-level effects on adolescent behavior. Moreover, they will provide policy-relevant information about how communities can attenuate or magnify family and school influences on adolescent drug use and delinquency.